The Greatest Gainer on the T40 chart this week will be Luis Fonsi & Daddy Yankee's "Despacito" f/Justin Bieber (UMLE/RBMG/DefJam/Republic ) as it moves inside the Top 10. Halsey's "Now or Never" (Astralwerks/Capitol) is looking to join the Top 10 with a leap right to the edge, at #11. Miley Cyrus' "Malibu" (RCA) breaks into the Top 20, along with Jason Derulo's "Swalla" f/Nicki Minaj & Ty Dolla $ign (Beluga Heights/Warner Bros.). Camila Cabello's "Crying In The Club" (Syco/Epic) goes Top 30. Glassnote's Childish Gambino charts this week with "Redbone," along with Katy Perry's "Swish Swish" f/Nicki Minaj (Capitol).